1. Field of the Invention
The invention pertains to the use of magnets, preferably permanent magnets, to efficiently utilize, regulate, and control magnetic forces in a motor or generator to increase the efficiency of the machine.
2. Description of the Related Art
In a conventional electric motor, the electromotive force (EMF) generated by the motor is 180xc2x0 out of phase with the input voltage with respect to the waves of the generator and input voltages. This is because the electromechanical coupling which produces torque between the motor rotor and stator core and coil members generates the exact opposite EMF in the coils as the applied current which creates a coupling. This is the basic nature of conventional electric motors and generators.
In order for an electric motor to run, the input voltage at any revolution must be greater than the reverse generated voltage at that rate of revolution (RPM). A current will be established in the coils of a motor which is proportional to the difference between the applied voltage and the reverse generated voltage. For example, if the reverse generated voltage is 100 volts at 1800 RPM and 120 volts are being applied to the motor, then the amperage established in the coil will be that which can be accounted for by 20 volts at the ohms and inductances of the motor coils at that RPM. This is why a motor with a large number of turns cannot run but very few RPMs or produce little torque at low voltages. The moment the rotor starts moving in relation to the stator, it takes only a few RPMs to generate a reverse voltage nearly as great as the applied voltage. Since the rotor cannot turn any faster without generating a voltage higher than the applied voltage, and thus stopping the current flow through the coils all together, the motor cannot achieve any useful RPM or torque without the application of higher voltages. So even though high turn coils produce higher flux per-amp of current circulating, ampere-turns, they also generate more reverse EMF and thus require higher voltage. A new and more effective way of interacting with these counter electromotive forces is one of the primary benefits to which the invention is directed.
The basic object of the invention is to provide an electric machine using a stator and rotating rotor wherein magnetic flux forces producing reverse electromotive forces are substantially eliminated or beneficially re-phased in an economical and practical manner to significantly increase the efficiency of operation of electrical machines such as motors and generators.
With the invention, permanent magnets are used in a flux-circuit in a manner similar to how a diode is used in an electrical circuit, and for this reason, the electrical machine of the invention is called a flux diode motor.
The invention uses permanent magnets in a stator or rotor assembly, or in a rotor assembly in proper relation to a stator assembly, so as to prevent the establishment of magnetic flux circuits in one direction and to encourage them in the opposite direction in certain areas of the rotor or stator assembly. This concept allows for a unique method of creating useful magnetomechanical coupling between the stator and rotor assemblies so as to produce a useful output at the rotor shaft, and unique generation of in-phase electromotive force in the stator or rotor coil or coils, depending on the design, in regard to the applied current.
The purpose of the invention is to develop an EMF machine which beneficially re-phases or eliminates the counter generation discussed above. It is apparent that if the counter generated EMF can be beneficially re-phased or eliminated, significant improvement in motor efficiency can be achieved as all of the applied voltage producing current in the motor coils, less coil inductance, will produce current flow. Further, in addition to eliminating or re-phasing the above discussed reverse generation, the practice of the invention produces a beneficial forward (in-phase) generation ahead of or behind the applied voltage. This arrangement results in a machine having very high efficiency. The forward generation creates a current xe2x80x9cpathxe2x80x9d through the motor coils which is in-phase with the applied voltage. The result is that this forward EMF creates, underneath the influence of its current wave, a nearly resistance-less, timed current-path through the coil as a sine-wave. No matter how many turns are on the motor coils, as long as the coils are not physically too large to where the flux from the permanent magnets cannot generate a forward EMF on the outer turns of the coil efficiently due to too great a distance, they will generate this nearly resistance-less path at the same ratio to turns. As the number of turns go up, so does the in-phase forward-generation current, and since none of the coils or magnets of this type of motor move, the forward generation comes from these non-moving parts, and it puts no load on the rotor when the right kind of electronic triggering circuits are used.
The control of flux in accord with the invention is achieved by the use of permanent magnets arranged in a particular manner with each other and with magnetic flux shunts so that the magnets and shunts can function as unidirectional flux xe2x80x9cgatesxe2x80x9d, which can be used to manage flux much like diodes manage electric current.
It is commonly understood that a permanent magnet pole will only pass flux in one direction, i.e. from the south pole to the north pole. The magnet will not allow flux to pass from the north pole through to the south pole. Thus, if you have oppositely polarized poles on a magnet or multiple magnets arranged with their poles opposite in polarity, or in some way oriented differently, then you have a one-way flux xe2x80x9cgatexe2x80x9d which can be used to manage flux similar to the manner that multiple diodes manage electrical current.
It is commonly understood that a permanent magnet pole will function as above as long as the flux it opposes and re-directs in out-of-phase cycle does not exceed its coercive force. However, it has been demonstrated that often magnets can be driven well beyond their coercive force rating without any demagnetizing effect to the magnet as long as it is in the presence of at least one oppositely oriented adjacent pole in the same applied flux path. This is because permanent magnets do not merely xe2x80x9cpassxe2x80x9d flux in the south to the north pole direction; they provide a resistance-less flux path, a kind of xe2x80x9csuperconductivityxe2x80x9d which attracts it. Thus, if one pole is in-phase with the applied flux, this will cause the applied flux and the flux of the in-phase pole to series. The result is that little demagnetizing force is exerted on the out-of-phase pole since the flux is attracted to the other pole. The in-phase pole offers little to no resistance while the out-of-phase pole offers high resistance. But it can still be understood that because there is a path through the in-phase pole for the applied flux to complete its magnetic circuit, then this will channel the full impact of the demagnetizing effect of the applied flux away from the out-of-phase pole. Therefore, this flux-diode type use of the magnets seldom, if ever, results in demagnetization of the permanent magnets. In fact, it tends to maintain the magnets at their peak magnetization because of the in-phase re-enforcement by the applied current to the magnetic poles"" polarization.
Another reason congruent with this phenomenon is the fact that the presence of a near or adjacent oppositely polarized pole will allow the out-of-phase pole to complete its magnetic circuit through the adjacent pole while being opposed to the applied flux. When the applied flux is flowing through this adjacent in-phase pole, the magnetic conductivity of that pole is increased and it therefore xe2x80x9cdrawsxe2x80x9d or xe2x80x9cattractsxe2x80x9d the flux of the out-of-phase magnetic pole to itself more powerfully. Since this is the normal state of how most of the flux of the oppositely phased permanent magnet poles respond to each other, when not under any outside influence, it is not a totally imposed or unnatural condition for the flux circuit for the out-of-phase pole. Thus, in accord with the invention, the magnets perform very well and their fields remain stable under these conditions without any evidence of demagnetization due to use.
In the practice of the invention, the stator or rotor, or the stator/rotor combination assemblies, are so constructed as to create torque by summing applied flux from the coil(s) and the flux of the permanent magnet(s) poles. For example, when the flux diode configuration is designed into the stator, the magnets become the conductive material of the stator around which the stator coil is wound. In such instance, the flux of the stator magnets take their normal paths and complete their paths through each other. When the stator coil is xe2x80x9conxe2x80x9d in one direction or the other, the flux from the stator coil is channeled through the in-phase poles and the flux of the in-phase poles is summed with the stator coil flux and thus conforms its path to that of the stator coil flux. The permanent magnet flux from the in-phase poles generates an EMF as it changes its geometric configuration. This generated EMF, when the apparatus of the rotor and stator is combined, has a relationship to the rotor and stator functional interdependent design which develops a forward EMF ahead of or following the applied run-current to the motor. By the use of periodically applied current with trailing voids (time following an applied current where there is no current to the motor at all), with the configuration of this invention, it is possible to re-phase these counter EMF""s so they become beneficial to the application of current, or getting torque out of the motor, rather than detrimental. The out-of-phase poles in each cycle xe2x80x9cshuntsxe2x80x9d back through the in-phase pole.
The type of rotor used in accord with the invention can be of several types. It can have permanent magnet poles or soft magnetic poles such as laminated or insulated soft iron poles. It can have coils or no coils. The type of rotor used is determined by the type of stator used. The number of poles on the rotor is determined by the number of magnetic poles used on the stator magnet(s). If the stator magnet(s) have four poles, then the rotor will have two poles. If the stator magnet(s) have eight poles on each magnet, then the rotor will have four poles, etc. In this embodiment of the apparatus, the rotor will always have one-half of the number of poles of their stator magnet(s). The interaction of the stator magnets and coils with the rotor is necessary to understand in regard to the uniqueness of the invention. Referring to the rotor poles as laminated shunts, as is descriptive of their function in relation to the magnetomechanical coupling between the rotor and stator magnet poles and the stator coil(s). They provide a connection (a ferromagnetic path) for the permanent magnet and coil flux. The magnetic polarity of each pole of each magnet is used like a flux diode to create different flux circuits. The permanent magnet pole will only allow flux from the stator coil to pass in one direction (as long as the flux density applied by the stator coil to the flux circuit does not exceed the coercive force of the magnet). Thus, the alternating flux from the stator coil(s) is channeled through the poles of the magnet(s) to create a spinning magnetic field. The laminated shunts of the rotor follow this spinning magnetic field.
As the laminated shunts of the rotor follow the spinning stator field creating continuous torque on the motor shaft, they not only xe2x80x9cshuntxe2x80x9d between magnets and thus create a ferromagnetic path for the coil flux, but also xe2x80x9cshuntxe2x80x9d between the poles of the same magnet. It is the alternating pattern of these two different types of xe2x80x9cshuntingxe2x80x9d which plays a major role in creating the unique and important characteristics of the inventionxe2x80x94in-phase generation. These two kinds of xe2x80x9cshuntingxe2x80x9d will be easier to distinguish if they are named. Accordingly, the shunting between adjacent poles on the same magnet will be called xe2x80x9cadjacent shuntingxe2x80x9d. The setting up of a flux path through and around the stator coil by xe2x80x9cshuntingxe2x80x9d with the in-phase poles of the same polarity on magnets behind or in front of a magnet""s poles, and/or summing of the in-phase poles of a magnet(s) with the stator coil flux will be called xe2x80x9cin-line shuntingxe2x80x9d.
The alternating pattern of these two shunting effects and the alternating flux of the stator coil(s) creates a combined pattern. If X is the flux from the stator coil which travels through the N-S poles of each stator magnet(s), and if O is the opposite flux from the stator coil which travels through the S-N poles of each stator magnet(s), then in combination with the flux from the stator magnets and the two different kinds of shunting described above, the pattern is as follows:
When the motor is running, the rotor shunts are torqued from the center of one set of in-line magnet poles to the center of the next adjacent set of in-line magnet poles. If we begin the description with the rotor shunts in the center of the S-N poles"" faces, it is at this point that the stator coil passes its X flux through its center and the magnets direct the flux to the N-S flux circuits. As a result, there is more flux density passing through the N-S poles of each magnet than the S-N poles. This causes the flux from the N-S poles to sum with the stator coil flux thus causing in-line shunting of all the N-S oriented poles in the stator coil. This also causes the flux from the S-N poles to shunt very tightly through the nearest adjacent N-S pole. The result is very high flux density in the N-S poles with an in-line orientation due to their own magnetism and the stator coil""s flux. The presence of the flux from the adjacent poles shunting through the N-S poles also increases their flux density.
Under these conditions, a strong torque is exerted on the rotor shunts, which are in the air gap between the magnets, to move them from the center of the S-N magnet pole faces to the center of the N-S pole faces. This is due to two flux interactions: 1) as all the S-N magnet poles flux is moving to adjacent-shunting through the N-S magnet poles, this exerts a torque on the rotor shunts, which on its own would move the rotor shunts between the S-N and the N-S poles faces; 2) at the same time, the concentration of flux in the N-S pole faces, creating high flux density and in-line orientation of all the N-S flux and coil flux, is torquing on the rotor shunts in the same direction to pull them to the center of the N-S pole faces.
As the rotor shunt reaches the center point between the two adjacent pole faces, the applied current is turned xe2x80x9cOffxe2x80x9d and the motor run-circuit shunts (shorts) the stator coil back to itself. What happens next depends on the load and applied voltage and current levels under which the motor is running. If it is under light load, and thus lower current levels, one kind of flux condition occurs. If it is under heavy load, and thus higher current levels, then a different flux condition is created. In between a light or heavy load, the motor moves linearly between the one and the other of these two conditions and exhibits characteristics of both in a xe2x80x9cseesawxe2x80x9d manner (as one set of characteristics is decreasing, to the same extent the other set increases).
First, if the motor is under light load, the nature of the counter-EMF in the stator coils is such that with the rotor shunts moving between the S-N and N-S pole faces, the applied current has been driven to zero. When the circuit turns the applied current xe2x80x9cOffxe2x80x9d at this point, there is no current in the coil to cause a forward EMF and the flux established in the coil will not collapse and cause a forward EMF because of the rotor shunts moving into place to reinforce the in-line shunting configuration. Even through the stator coil flux will now start to decline, the rotor shunts are still being torqued by the concentration of flux created in the N-S pole faces. This causes the rotor shunts to continue moving to the center of the N-S pole faces, and as they do so, reinforcing the in-line shunting of the N-S pole faces, this causes the N-S pole""s flux to continue to expand outward through the stator coil, which is shorted to itself, and this generates a current in this trailing void (time period following the former applied current wave in which no current is applied to the motor coil) which is in the same direction as the next applied current wave which is to follow it.
This current is generated by the non-moving magnets and the magnetomechanical relationship of the rotor to the torque flux is such that it not only does not put a load on the rotor, it continues the torque which was initiated by the previously applied current. Thus the torque output is continued even while this current wave is being generated in the opposite direction.
Since the stator coil is shorted to itself, the generation by this continuing expansion of the magnet flux of the N-S poles results in only enough voltage to pass its current through the circuit (about 1 volt) and the rest of the EMF potential is transformed into current flow in the coil. This generates the beginning of the other side of the sine-wave and overcomes the inductance to the establishment of current in that direction through the stator coil.
When this part of the other side of the sine-wave is at its zenith, the rotor shunts have reached the center of the N-S pole faces. At this point, the circuit applies current in the same direction as the expanding magnets have been generating (which is the opposite of the previously applied current) and because the current is already established in the coil by this generation, the applied current wave encounters no inductance at all to establishing itself up to the level of the generated wave which preceded it. This results in an instantaneous rise of the applied current in the coil with no inductive slope at all. This applied current direction results in the stator coil generating the O flux through its center which is controlled and directed by the magnets through the S-N poles. This causes the N-S poles to lose the in-line shunting configuration and collapse in through the coil and into an adjacent shunting configuration through the S-N poles, and the series-ing of the S-N poles with the stator coil flux causes high flux concentration in the S-N poles. This results in the rotor shunts beginning to torque from the face of the N-S poles to the face of the S-N poles.
The above is a description of what takes place if the motor is under light load and low current application. Going back now to the same point in the motor""s rotational phases where beginning describing the light load characteristics (the rotor shunts are at the center point as they move between the S-N and N-S pole faces, and the current has just been turned xe2x80x9cOffxe2x80x9d by the circuit, and the stator coil shorted to itself), described below are heavy duty characteristics.
If the motor is under heavy load, then when the current is turned xe2x80x9cOffxe2x80x9d as the rotor shunts reach the center point between the S-N and the N-S pole faces, and the stator coil is shunted (shorted) back to itself, the current in the stator coil is at its peak because of the greater applied voltage and the flux expansion of the N-S poles has been accelerated to maximum through the stator coil. As the flux expansion of the N-S poles by the stator coil is now greater than that which the rotor shunts can maintain by themselves, when the circuit shorts the stator coil, it results in a very large forward EMF being generated by the collapsing field of both the coil and the magnet poles. Since the N-S pole flux can only collapse down to the level which the rotor shunts can maintain as they move into the center of the N-S pole faces, the flux intensity goes down slowly thus continuing a very strong torque on the rotor shunts which are moving to the center of the N-S pole faces. The generated current in the coil keeps reestablishing the field which is trying to collapse and thus lags its collapse.
Since this takes place from the center point between the two adjacent pole faces and the center of the N-S pole faces, it is in the last half of the mechanical torque cycle (remember the rotor shunts are torqued from the center of one set of poles to the center of the next adjacent set of poles.) This adds much to the torque output during this cycle even though there is not power being applied to the motor. Also, there are no counter EMF""s during this part of the cycle to counteract this forward EMF and the work it is doing. This results in great efficiency increase in the motor""s output.
As the rotor shunts reach the center of the N-S pole faces, the flux in the N-S poles has collapsed as far as the rotor shunts will allow, bringing the forward generated EMF in the coil to near zero. At this point, the current is turned xe2x80x9cOnxe2x80x9d by the circuit in the opposite direction. This results in the stator coil generating the O flux through its center which is controlled and directed by the magnets through the S-N poles. This causes the N-S poles to lose the in-line shunting configuration and collapse in through the coil and into an adjacent shunting configuration through the S-N poles, and the series-ing of the S-N poles. This results in the rotor shunts beginning to torque from the face of the N-S poles to the face of the S-N poles.
Depending on the load and applied current characteristics, the torquing of the rotor shunts from the center of the N-S pole faces to the center of the S-N pole faces will repeat what is described above only in opposite polarity, resulting in the rotor shunts once again being positioned over the S-N pole faces. The cycle then repeats.
The above description will become clearer upon description of the embodiments of the invention illustrated and described below. However, the electrical aspects of a motor utilizing the inventive concepts can be appreciated from FIGS. 8-11, which show center-point triggering of the motor circuit, which will be explained and distinguished from stern-point triggering of the motor circuit later in this application.
FIG. 8 illustrates a sine-wave representing the EMF generated in the motor coil when the motor is running. This sine-wave is perfectly in-phase as a forward EMF with the applied voltage and current which creates motor torque. In FIG. 9, the applied voltage is represented. This applied voltage is about 60 percent of each half-cycle. FIG. 10 represents the appearance of the applied current (amps). It will be noted that since the applied power does not come on until about 20 percent into the half-cycle wave of the forward EMF, that when the voltage is applied, the current goes instantly to the level of the forward generation, and this demonstrates the inductance effect in a 2600 turn stator coil is xe2x80x9c0xe2x80x9d up to the level of influence of the forward EMF. Accordingly, there is no current rise slope. FIG. 11 represents the overlaying of FIGS. 8 and 10.
Notice that on the back half of the applied current wave, FIG. 10, that even though the square-wave applied voltage stays at the same level, the current flow through the coils follows exactly the sine-wave-effect of the forward EMF. This demonstrates that the forward EMF is primarily responsible for the current flow, and is what creates a conductance through the coil, not merely the applied voltage. By the practice of the invention, very low voltages can be used to put useful current levels through very high-turn-coils without the usual level of counter EMF being generated to shut the motor coil down. Thus, very high ampere-turns can be achieved at very low watts.
One of the unusual characteristics of the invention is how the forward EMF, a generated EMF produced during the torque cycles of the motor before or after the applied current which is in perfect phase with the applied voltage and current, interacts with the applied current. To the inventors"" knowledge, there is no other known electric motor which has this characteristic.
If an electric machine in the form of a generator utilizing the invention is rotated at about 4000 RPM, totally unloaded and having an open circuit, it will generate a voltage potential of around 50 volts. If the stator coil is then shunted to itself placing a maximum load on the circuit, the voltage will drop to around 1 volt, and the resulting current flow from the stator coil will be about 0.200 amps RMS. However, since this generated current is always in phase with any voltage or current applied to the device when it is used as a motor, and since any voltage and current source used, such as a power supply or a battery, is seen by the stator coil of the motor as a conducted connection (a dead short), this generated forward EMF flows through the circuit as almost 100 percent current and not voltage, similar to the shorting out of a generator. However, it does not create a load in the presence of an applied current. If the applied current and voltage is brought up to the point that the motor is running 4000 RPM (about 38 volts), the total current flow in the circuit will be 0.200 amps RMS, the same as the motor generates at that RPM when at maximum load, which is what the stator coil is seeing at that very moment as it is powered by the applied current source.
In normal circumstances, the circuit that is employed to apply power to the motor only applies power periodically to each half-cycle, and that, right in the middle of the forward-generated sine-wave when center-point triggering is used. When the circuit is not applying current to the stator coil, it shunts the stator coil to itself so that any generated current from the stator coil can flow back into the stator coil. The result is that the current-flow in the coil is a perfect sine-wave at all times, even though the applied current is a modified sine-wave with the front and back of each half-wave cut off. This demonstrates that the current generated from the stator coil supplies the needed current levels to maintain the full current flow in the circuit at all times.
One other important characteristic of the invention which contributes to greater efficiency is that the core for the stator is permanent magnets which makes for a per-saturated core to the level of the magnets br. This means that as the coil uses the in-phase magnet poles as its core, no energy is lost in saturating the stator core of these poles since they are already nearly saturated. And since none of the flux will pass through the out-of-phase poles, no energy is lost.
The result of the producing of electric machines such as motors and generators in accord with the inventive concept is to provide very high efficiency machines even of small and fractional horsepower. Such machines produce the desired torque output without the creation of appreciable heat resulting in long life and low operating costs. Embodiments utilizing the inventive concepts are described below.